Cassette for receiving optical waveguides with overlengths and fiber splices

ABSTRACT

The invention relates to a cassette (KA) or cassette base plate (KG) for receiving optical wave guides with over-lengths. Additional elements for entries, pivoting elements and fixing elements which can be removed if needed, respectively, are located on said cassette base plate (KG). This ensures that the cassettes (K) or cassette base plates (KG) are universally usable.

FIELD OF THE INVENTION

This invention relates to a cassette for accommodating opticalwaveguides with excess lengths and optical waveguide splices, break-outwebs and circular guide elements for the optical waveguides introducedand splice fixing means for the optical waveguide splices being arrangedon a cassette base plate.

BACKGROUND OF THE INVENTION

EP 0 872 750-A2 discloses a cable sleeve with a retaining arrangementfor cassettes for storing and splicing optical waveguides. Theindividual cassettes are arranged for swing action on a cassettecarrier, the cassettes being arranged one above the other and beingcapable of being swung upward into operating positions. Two circularguide elements with break-out webs are located on the cassette baseplate, with the result that it is ensured that optical waveguidesintroduced cannot spring out of position.

DE 44 38 668-A1 discloses a cassette which is intended for storingoptical-waveguide excess lengths and optical waveguide splices andcomprises one or more basic modules. These basic modules are each of thesame basic construction and may be assembled, depending on requirements,with the aid of connecting elements. Here too, circular guide elementsare provided for the optical waveguides.

WO 95/07482, furthermore, discloses a cassette for accommodating opticalwaveguides with excess lengths, the optical waveguides being introducedand/or led out at groove-like inlets. The excess lengths here may bepositioned around approximately circular guide elements. Here too,break-out webs prevent the optical waveguides introduced from springingout.

SUMMARY OF THE INVENTION

An object of the invention, then, is to provide a cassette foraccommodating optical waveguides with excess lengths that can be used,and is optimized, as universally as possible for a wide range ofdifferent use purposes in respect to the arrangement itself, in respectto the variety of inlet ports for the wide range of different types ofoptical waveguide and in respect to the accessibility.

One object set is achieved according to the invention by a cassette ofthe type mentioned in that there are provided two circular guideelements and a cross-form guide element, located between the twocircular guide elements, for the optical-waveguide excess lengths, inthat differently shaped splice-protection holders are provided foraccommodating different embodiments of splice-protection elements, inthat pivoting elements are provided both for vertical and for horizontalpivoting of the cassette, in that the introduction regions are equippedfor the introduction of optical waveguides and/or optical waveguidestrips and/or optical waveguide connectors, and in that additionalelements and/or accessories are arranged on the cassette base plate foradaptation to the respective use purpose.

One advantage of the cassette construction according to the inventionover the prior art is that this cassette can be used for accommodating awide range of different configurations of optical waveguides, such asindividual fibers, strips or bundle tubes or optical waveguideterminations, such as optical waveguide connectors, in particularso-called pigtails, which are optical waveguide ends with connectorsfixed thereon. A further advantage is that satisfactory guidance of theoptical waveguides introduced is ensured by two circular guide elements,which maintain in each case the permissible minimum radii of the opticalwaveguides, and by a cross-form guide element located therebetween, thepossibility of guidance in a FIG. 8 making it possible to reach everyoutlet and inlet point of the cassette. In the case of the introductionof optical waveguides with connector termination (pigtail), anaccommodating adapter may be inserted in front of the inlet ports of thecassette base plate, arrangements for accommodating the connectors beinglocated on said adapter. Likewise on this inlet side, a verticalpivoting element may be attached there, which makes it possible for thecassette base plate to be swung down laterally from a vertical position.A corresponding step-design holder for vertical pivoting makes itpossible to achieve the situation where, by virtue of cassette baseplates that are arranged one beside the other being pivoted downlaterally, access can be gained to said base plates without them havingto be removed from the cassette assembly.

A further advantage is that corresponding arrangements and installationsin the form of splice holders make it possible for all possible types ofoptical waveguide splice protectors to be fixed on the cassette baseplate. Moreover, additional elements or accessories are latched, orfixed by break-out webs, in the interiors of the circular guideelements, it being possible for these, depending on the use purpose andrequirements, to be removed or broken off. With the aid of theseadditional elements or accessories, it is possible to assemble, forexample, cassette base plates to form stacks, the access to eachindividual cassette base plate being maintained. For this purpose, forexample, hinge parts and closure clips are required. Moreover, mountsfor optical waveguide strips or individual optical fibers are fixed inthe same way in the interiors of the guide elements or accessories, itbeing possible for these, following removal, to be inserted into therespective regions of the inlet ports on the cassette base plate.Finally, in this exemplary embodiment, special fastening elements arealso provided as additional elements or accessories, it being possiblefor the cassette base plate to have these fitted on the outside, eitheron the narrow side or on the rear plate side. With the aid of thesefastening elements, it is then also possible for said cassette baseplate to be fitted, and fastened, on corresponding mating elements onthe framework or the like.

Furthermore, a cassette transition is provided in the central region ofthe cassette base plate, on the longitudinal pivoting side, it beingpossible for optical waveguides to be passed on from one cassette to aparallel cassette by way of said transition.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail hereinbelow, withreference to a plurality of embodiments, in 28 figures.

FIG. 1 shows a closed cassette base plate with a vertical pivotingelement.

FIG. 2 shows a first embodiment of an open cassette base plate with anaccommodating adapter for optical waveguides with connectorterminations.

FIG. 3 shows a second embodiment of an open cassette base plate with avertical pivoting element.

FIG. 4 shows the vertical pivoting element.

FIG. 5 shows a holder for accommodating the vertical pivoting elements.

FIG. 6 shows a vertical arrangement of a plurality of cassette baseplates.

FIG. 7 shows an accommodating holder for optical waveguide connectors.

FIG. 8 shows a detail of an accommodating adapter for the introductionof connectors of large diameter.

FIG. 9 shows a detail of an accommodating adapter for the introductionof connectors of small diameter.

FIG. 10 shows an arrangement of splice-protection holders forshrink-tube splices.

FIG. 11 shows an arrangement of splice holders for optical waveguidestrips.

FIG. 12 shows the arrangement of splice holders for crimp splices andFibrlok™ devices.

FIG. 13 shows an arrangement of splice-protection holders forshrink-tube splices and Fibrlok™ devices.

FIG. 14 shows a mount for optical waveguide couplers.

FIG. 15 shows an inlet and/or outlet region of the cassette base plate.

FIG. 16 shows a mount for bundle tubes.

FIG. 17 shows additional elements within a circular guide element.

FIG. 18 shows a mount for individual fibers.

FIG. 19 shows a cassette transition.

FIG. 20 shows additional elements within a circular guide element.

FIG. 21 shows a stack of cassette base plates with accommodatingadapters.

FIG. 22 shows the end view of the stack in FIG. 21.

FIG. 23 shows the arrangement in FIG. 22 with a cassette base plate inthe upright position.

FIG. 24 shows the locking side of the arrangement in FIG. 21.

FIG. 25 shows the insertion of a fastening element on the narrow side ofthe cassette base plate.

FIG. 26 shows, as additional elements, the mounts for the inlet portsand the insertion of a fastening element on the underside of thecassette base side.

FIG. 27 shows the configuration of a cover for the cassette base plate.

FIG. 28 shows details of the holder for vertical pivoting elements.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a cassette base plate KG which is closed off by coverD and in the case of which a vertical pivoting element VS is attached toone narrow side. Arranged on the longitudinal swing-action side of thecassette base plate KG are hinge pins SS1 and SS2 into which it ispossible to clip additional elements in order for cassette base platesKG to be stacked one upon the other, as will be explained at a laterstage in the text. Arranged on the opposite narrow side of the cassettebase plate KG are fastening elements BE, into a sub-region of which itis possible to snap the cover closures DV, although they may also servefor the insertion of additional elements. Provided in the center of thecassette base plate KG is a stacking opening SO which also passesthrough the cover D and into which, for example, a stacking mandrel canbe guided.

FIG. 2 shows the cassette base plate KG in the open state, with theresult that it is possible to see the position of the two circular guideelements RF1 and RF2 with the cross-form guide element KF locatedtherebetween. The optical waveguides introduced may also be guided andstored in a FIG. 8 by way of these guide elements, this making itpossible for said optical waveguides to be guided to each inlet portand/or outlet port EF of the cassette base plate KG. The narrow side ofthe cassette base plate KG here is provided with an accommodatingadapter PTA for the introduction of optical waveguides with connectorterminations, e.g., so-called pigtails. The connectors are thenpositioned in the mounts A and fixed by clamping parts KT, which arelikewise arranged on said accommodating adapter PTA, such that they canbe broken off. In this case, the accommodating adapter PTA has alreadybeen fastened on the cassette base plate KG via a break-off edge BK, butit can be removed by being bent along said break-off edge BK. The coveris fastened for swing action on the cassette base plate KG by a coverhinge DS. It can also be seen in the illustration that arranged on theguide elements, as well as in the rest of the cassette base plate KG,are holding-down means NH and LNH, by means of which the opticalwaveguides introduced are prevented from springing out.

Provided in the central region of the cassette base plate KG aresplice-protection holders SH for different splice protectors, e.g. foraccommodating a shrink-tube splice SSH. For the longitudinal guidance ofoptical waveguides, in this region, holding-down means LNH are alsoincorporated in the arrangement of the splice-protection holders SH orSSH. Arranged in a corner region of the cassette base plate KG is a borefor a corner articulation EG, into which a pin can be plugged such thatit extends beyond a plurality of cassette base plates, this making itpossible for an individual cassette base plate KG to be pivoted out ofthe composite block.

FIG. 3 shows a cassette base plate KG with a vertical pivoting elementVS attached to the narrow side, by way of which the cassette base plateKG is latched into a special holder for such pivoting elements.Moreover, different a splice-protection holders are provided in turn. Acentral hole ZL is congruent with the stacking opening SO in the cover,which has been removed here. Screw-connection points SP allow fasteningusing screws.

FIG. 4 illustrates a vertical pivoting element VS which, for example, isintegrally formed on the narrow side of the cassette base plate KG. Thispivoting element VS is inserted into a corresponding holder by way ofthe hinge elements SE, a resilient latching-in action taking place byway of resilient elements FE in the form of longitudinally split pins.Moreover, a fixing nose FN is integrally formed on the pivoting elementand makes it possible to fix the vertical position of the cassette baseplate KG.

FIG. 5 shows the step-like holder RVS for the vertical pivotingelements, a double bore DBO-DBU, in which the bores merge one into theother, being made in each step of the fastening arrangement SBA. Theresilient elements of a vertical pivoting element are latched into saiddouble bore DBO-DBU, the resilient action allowing latching both in thetop bore DBO and in the bottom bore DBU. This makes it possible for thecassette base plates KG to be swung down laterally one above the otheruntil the desired cassette base plate KG or cassette K has been reached.Fixing in the vertical position takes place by way of the fixing nose FN(see FIG. 4) engaging in the fixing groove NFN. Arranged in the verticalreinforcing part of the holder HVS is a through-passage opening DFthrough which a fastening strap can be guided. The holder HVS may befastened in the framework by way of a fastening attachment BA.

FIG. 6, then, shows a composite arrangement of cassettes K, comprising acassette base plate KG with a pivoting element and a cover, which areretained vertically in the holder HVS by way of their vertical pivotingelements VS. One of these cassettes K has been swung out laterally intothe horizontal position, as is indicated by the arrow. The entirearrangement is fastened on a framework element GE by way of thefastening attachment BA.

FIG. 7 shows that the mounts A of the accommodating adapter PTA, foraccommodating optical waveguides with connectors such as pigtails, havetwo accommodating regions AB3 and AB900. The accommodating region AB3 isconfigured here, for example, for accommodating connectors of 3millimeters in diameter and the accommodating region AB900 is configuredfor accommodating connectors of 900 micrometers in diameter, althoughother dimensions are also possible. Once the connectors have beenintroduced, they are fixed by the clamping parts KT, these havingalready been arranged on the accommodating adapter PTA such that theycan be optionally latched or broken off. It is possible for theaccommodating adapter to be broken off via the break-off edge BK if itis not being used.

FIG. 8 shows the accommodating region AB3 covered by way of an adaptedclamping part KT3.

By virtue of lateral latching noses RN2 in the mount A and correspondinglatching noses RN1 on the sides of the clamping parts KT, the connectorsintroduced are clamped with corresponding latching action. The radii Rof the accommodating regions are likewise adapted to the connectordiameter. The accommodating region AB900, which is located at the rear,is not used in this case. Guide rails FL make it easier for the opticalwaveguides to be introduced into the cassette base plate.

FIG. 9, then, shows an inlet port for connectors in the accommodatingregion AB900, a correspondingly adapted clamping part KT900 then alsohaving been inserted here. It is also shown here that the opticalwaveguides are guided by way of guide rails FL up to the inlet port EFof the cassette base plate KG.

FIG. 10 shows a central region of the cassette base plate KG withsplice-protection holders SHS for shrink-tube splices, which are fixedwith the aid of resilient clamping elements KE. Illustrated therebeneathare the cross-form guide elements KF with the holding-down means NH anda longitudinal lead-through, running between the splice-protectionholders SHS, for optical waveguides with holding-down means LNH.

FIG. 11 shows another central region of the cassette base plate KG witha splice-protection holder SHF for optical waveguide strips and alongitudinal guide for optical waveguides with holding-down means LNH.

FIG. 12 shows the combination of different splice-protection holders,e.g., splice-protection holders SHF for so-called Fibrlok™ devices(available from 3M) and splice-protection holders SHK for crimp splices.Introduced therebetween is a longitudinal guide for the through-passageof optical waveguides with holding-down means LNH.

FIG. 13, in turn, shows a possible combination of splice-protectionholders, in this case splice-protection holders SHF for Fibrlok™ devicesand splice-protection holders SHS for shrink-tube splices.

FIG. 14 illustrates that it is also possible to provide fixingarrangements for other optical waveguide elements, e.g., a mount AK foran optical coupler. A longitudinal lead-through with holding-down meansLNH is routed along the longitudinal side of the cassette base plate KG.

FIG. 15 shows the region of an inlet port EF on the cassette base plateKG in which it is possible to insert appropriate mounts for adaptationto the type of optical waveguide which is to be introduced. Arranged inthe side walls of the inlet ports EF are latching noses RN by means ofwhich the mounts are locked and fixed. In the openings of the inletports EF, rows of teeth ZR, for example, are provided in the radialregions and act counter to tensile stressing in the axial direction.Provided in the inner region of the inlet ports EF are rails and/orarrangements KBB on which it is possible to fasten cable ties for fixingoptical waveguides which have been introduced.

FIG. 16 shows a mount ABA for the introduction of bundle tubes BA. Thismount ABA is inserted into an inlet port EF according to FIG. 15 andlatched laterally. Following the introduction of the bundle tube BA, aclamping element KBA is fitted in order to fix the bundle tube BA.

FIG. 17 shows the interior of a circular guide element RF1, the boundarywall being of a diameter which corresponds to the minimum permissiblebending radius for optical waveguides. Holding-down means are attachedto the outside for the optical waveguides introduced. In the interior ofsaid circular guide element RF1, then, additional elements are arrangedsuch that they can be removed, to be precise they are either latched inor fixed by way of break-out webs AST. If required, then, theseadditional elements may be removed and used for the appropriateapplication. Fixed in said interior, for example, are two mounts ABA forbundle tubes and the two associated clamping elements KBA. Also locatedtherein are a cutout ASB and a support KBEG for the insertion of afastening element KBE (see FIG. 20). The fastening element KBE islatched in here such that it projects rearward through the cassette baseplate KG.

FIG. 18 illustrates a further mount AEF, which can likewise be insertedinto an inlet port EF. It contains an adapter AD for the introduction ofindividual fibers or optical waveguide strips, which are introducedthrough slits S. The slits S are closed off at the top by a cover AEFD.

FIG. 19 demonstrates that additionally arranged in the central region ofthe narrow side of the cassette base plate KG is an opening for acassette transition KU for optical waveguides. This cassette transitionKU is on the pivoting side of the cassette base plate KG, with theresult that it is not possible to damage the led-out optical waveguidesin the composite stack arrangement of a plurality of cassette baseplates during swing action. The optical waveguides preferably make thetransition in buffer tubes, which are fixed on latching noses RNAS.

FIG. 20 shows a second circular guide element RF2, in which, in turn,different individual parts are arranged as removable additionalelements. Hinge parts ST, for example, are arranged here via break-outwebs AST, which are required for the swing-action stack construction ofa plurality of cassette base plates KG. These hinge parts ST are clippedonto the hinge pins SS1 and SS2 by way of their openings OSS (see alsoFIG. 22). Provided on each hinge part ST is a stop RNGL, which preventsa swung-out cassette base plate from being swung open too far. Alsolocated here are cassette-fastening elements KBE, by means of which thecassette base plate can be fitted, and fastened, on framework parts. Forthis purpose, the undercut latching elements HRE are introduced intocorresponding mating latching formations. Finally, closure clips VK areprovided, these being latched into the outer fastening elements BE ofthe cassette base plates in order that a stack comprising a plurality ofcassette base plates can be clamped together to form a fixed unit.

FIG. 21, then, shows a stack of, for example, three cassette base platesKG, which are additionally provided with accommodating adapters PTA. Theclosure clips VK, included as additional elements, have been latchedinto the fastening elements BE of the cassette base plates KG and theuppermost cassette base plate KG is covered by a cover D, the closure DVof which likewise engages in a fastening element BE. This makes itpossible to assemble a compact unit which can be mounted rotatably, forexample, in a continuous corner articulation EG.

FIG. 22 shows, in detail form, the arrangement of the hinge part STattached with latching action in the direction of the hinge pins SS1 andSS2 of the cassette base plate. When the cassette base plates KG1, KG2etc. are swung open, the lateral latching noses RNG of the cassette baseplates slide in supports RNGL of the hinge parts ST until they come to astop.

FIG. 23 illustrates that, for example, the cassette base plate KG2 hasbeen swung open through 90° C., the latching noses RNG sliding insupports RNGL until they come to a stop.

FIG. 24, once again, shows the opposite side of the stack of cassettebase plates KG1, KG2 and KG3, from which the reciprocal interengagementof the closure clips VK in the fastening elements BE can clearly beseen. In this case, the cover closure engages in the fastening elementBE of the uppermost cassette base plate KG3.

FIG. 25 shows a cassette-fastening element KBE fitted into a fasteningelement BE on the outer longitudinal side of the cassette base plate KG.The cassette base plate KG can be fitted into a corresponding support ofa framework by way of the undercut knob of the cassette element KBE.

FIG. 26 shows that the cassette fastening element KBE can also belatched in a cutout ASB in the base part of the cassette base plate KG,the cassette-fastening element KBE being latched in the support KBEG.

FIG. 27 shows the configuration of a cover D for the cassette base platewhich is latched in by way of cover hinges DS. The opposite side isprovided with the cover closures DV. It is possible for a mandrel to beguided through the central opening SO and to have a plurality ofcassette base plates stacked on it.

FIG. 28 shows, once again, in detail form, the step-like holder HVS foraccommodating vertical pivoting elements which are latched into thedouble bores DBO-DBU by way of their resilient elements. Also providedare transversely running grooves NFN for the insertion of the fixingnoses FN of the vertical pivoting elements, in order for it to bepossible for the cassette base plates to be retained in the verticalposition.

What is claimed is:
 1. A cassette for accommodating optical waveguideswith excess lengths and optical waveguide splices, comprising: acassette base plate; two circular guide elements arranged on thecassette base plate and at least one cross-form guide element locatedtherebetween; break-out webs disposed within the circular guideelements; splice-protection holders for accommodating splice-protectionelements; at least one pivoting element for pivoting of the cassette;and at least one inlet region for the introduction of optical waveguidesinto the cassette.
 2. The cassette as claimed in claim 1, wherein the atleast one pivoting element is arranged on a narrow side of the cassette.3. The cassette as claimed in claim 2, further comprising anaccommodating adapter disposed on the narrow side of the cassette forconnectorized optical waveguides.
 4. The cassette as claimed in claim 1,further comprising a vertically running opening for accommodating astacking mandrel.
 5. The cassette as claimed in claim 1, furthercomprising a cover that is pivotable along a hinge side of the cassette.6. The cassette as claimed in claim 5, further comprising at least onehinge pin disposed along the hinge side of the cassette.
 7. The cassetteas claimed in claim 6, wherein the at least one hinge pin is furthersubdivided into two hinge pins by a web.
 8. The cassette as claimed inclaim 1, further comprising a corner articulation disposed on at leastone corner of the cassette.
 9. The cassette as claimed in claim 1,further comprising holding-down means disposed on at least one of thecircular guide elements, the cross-form guide element, at least onelateral wall of the cassette, and a base part of the cassette.
 10. Thecassette as claimed in claim 1, wherein the splice-protection holdersaccommodate one or more optical splices.
 11. The cassette as claimed inclaim 1, further comprising a mounting element for holding opticalwaveguide couplers.
 12. The cassette as claimed in claim 1, wherein theat least one inlet region comprises four inlet regions and wherein atleast one inlet region is arranged at a corner region of the cassette.13. The cassette as claimed in claim 1 further comprising accessoriesremovably fixed to the cassette by the break-out webs.
 14. The cassetteas claimed in claim 13, wherein the accessories are disposed in at leastone of the circular guide elements.
 15. The cassette as claimed in claim1, further comprising fastening elements disposed on the cassette. 16.The cassette as claimed in claim 3, wherein the accommodating adapterhas accommodating regions adjacent one another to accommodate connectorsof different diameters.
 17. The cassette as claimed in claim 16, whereinthe accommodating regions are formed by parallel grooves that generallycorrespond to the diameters of the connectors.
 18. The cassette asclaimed in claim 17, wherein each groove has at least one steppedformation from a first diameter to a second diameter.
 19. The cassetteas claimed in claim 13, wherein the accessories include adapted clampingparts, the clamping parts being removably fixed on an accommodationadapter to hold at least one connector.
 20. The cassette as claimed inclaim 1, wherein the pivoting element has at least one hinge element,the hinge element having latchable resilient elements and a fixing noseto allow for vertical pivoting.
 21. The cassette as claimed in claim 20,further comprising a holder to engage the latchable resistant elements,the holder having double bores in communication with one another andarranged in a staircase configuration to accommodate pivoting elementsof a plurality of cassettes.
 22. The cassette as claimed in claim 1,further comprising securing elements at the at least one inlet region tosecure the optical waveguides.
 23. The cassette as claimed in claim 1,further comprising a mount and a corresponding covering clamping elementto secure bundle tubes, the mount and covering clamping element beinginsertable into one or more insert ports and removably secured in atleast one circular guide element.
 24. The cassette as claimed in claim1, further comprising at least one cassette-transition opening disposedin a central region of the cassette, the cassette-transition openinghaving protrusions therein to engage buffer tubes introduced into thecassette-transition openings opening.
 25. The cassette as claimed inclaim 1, further comprising at least one cassette-fastening elementremovably fixed on a circular guide element, the at least onecassette-fastening element having an undercut latching element to engagea frame.
 26. The cassette as claimed in claim 1, further comprisinghinge parts removably fixed in at least one circular guide element, thehinge parts configured to engage the cassette for the construction ofswing-action cassette stacks, whereby the hinge parts have latching-nosesupports as stops for latching noses of a corresponding cassette. 27.The cassette as claimed in claim 1, further comprising closure clipsremovably fixed in at least one circular guide element, the closureclips configured to engage one or more lateral fastening elementsdisposed on the cassette.